sched/cache: Keep nr_pref_llc_running in the runnable domain, to fix LLC mis-scheduling buggrafted

alb_break_llc() decides whether to break LLC preference during active
load balance. It does so by testing that every runnable fair task on the
source rq prefers its LLC:

	env->src_rq->nr_pref_llc_running == env->src_rq->cfs.h_nr_runnable

But the two counters cover different sets. nr_pref_llc_running is updated
in account_llc_enqueue()/account_llc_dequeue(), next to cfs_rq->nr_queued,
so it follows queued tasks. h_nr_runnable is updated in set_delayed()/
clear_delayed() and drops delay-dequeued tasks.

So under DELAY_DEQUEUE, a preferring task that goes to sleep stays counted
in nr_pref_llc_running while h_nr_runnable falls. The equality then breaks,
alb_break_llc() returns false, and active balance is free to pull a task
off its preferred LLC. Active balance only moves runnable tasks, and this
is the only LLC check it consults: once the stopper runs, LBF_ACTIVE_LB
skips the per-task test in can_migrate_task(). The runnable set is the one
we want.

Fix it on the counter side. A task should be counted in
nr_pref_llc_running exactly while it is both queued on its preferred LLC
(pref_llc_queued) and runnable (!sched_delayed). Define that membership
once in task_pref_llc_runnable(), and adjust the counter only through
pref_llc_running_inc()/pref_llc_running_dec() from the four sites that
change either input: account_llc_enqueue(), account_llc_dequeue(),
set_delayed() and clear_delayed(). Gating every update on the same
predicate keeps the delay, wake and dequeue paths from double-counting
or underflowing; see the comments at those sites for the ordering.

nr_llc_running and sd->llc_counts are not touched and stay on queued
semantics.

Fixes: 714059f79ff0 ("sched/cache: Handle moving single tasks to/from their preferred LLC")
Closes: https://lore.kernel.org/lkml/20260827135000.735138-1-zhanxusheng@xiaomi.com/
Reported-by: Zhan Xusheng <zhanxusheng@xiaomi.com>
Suggested-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Kayra Cizmeci <kayracizmeci@gmail.com>
Cc: <stable@kernel.org> # v7.2.x
Link: https://patch.msgid.link/06af61afedac32e6477f57feb4d658f6c411c3af.1790035273.git.tim.c.chen@linux.intel.com

1 files changed, 99 insertions, 0 deletions

diff --git a/Documentation/gpu/kms-properties.csv b/Documentation/gpu/kms-properties.csv
new file mode 100644
index 000000000..bfbfbf4f1
--- /dev/null
+++ b/Documentation/gpu/kms-properties.csv
@@ -0,0 +1,99 @@
+Owner Module/Drivers,Group,Property Name,Type,Property Values,Object attached,Description/Restrictions
+,DVI-I,“subconnector”,ENUM,"{ “Unknown”, “DVI-D”, “DVI-A” }",Connector,TBD
+,,“select subconnector”,ENUM,"{ “Automatic”, “DVI-D”, “DVI-A” }",Connector,TBD
+,TV,“subconnector”,ENUM,"{ ""Unknown"", ""Composite"", ""SVIDEO"", ""Component"", ""SCART"" }",Connector,TBD
+,,“select subconnector”,ENUM,"{ ""Automatic"", ""Composite"", ""SVIDEO"", ""Component"", ""SCART"" }",Connector,TBD
+,,“mode”,ENUM,"{ ""NTSC_M"", ""NTSC_J"", ""NTSC_443"", ""PAL_B"" } etc.",Connector,TBD
+,,“left margin”,RANGE,"Min=0, Max=100",Connector,TBD
+,,“right margin”,RANGE,"Min=0, Max=100",Connector,TBD
+,,“top margin”,RANGE,"Min=0, Max=100",Connector,TBD
+,,“bottom margin”,RANGE,"Min=0, Max=100",Connector,TBD
+,,“brightness”,RANGE,"Min=0, Max=100",Connector,TBD
+,,“contrast”,RANGE,"Min=0, Max=100",Connector,TBD
+,,“flicker reduction”,RANGE,"Min=0, Max=100",Connector,TBD
+,,“overscan”,RANGE,"Min=0, Max=100",Connector,TBD
+,,“saturation”,RANGE,"Min=0, Max=100",Connector,TBD
+,,“hue”,RANGE,"Min=0, Max=100",Connector,TBD
+,Virtual GPU,“suggested X”,RANGE,"Min=0, Max=0xffffffff",Connector,property to suggest an X offset for a connector
+,,“suggested Y”,RANGE,"Min=0, Max=0xffffffff",Connector,property to suggest an Y offset for a connector
+,Optional,"""aspect ratio""",ENUM,"{ ""None"", ""4:3"", ""16:9"" }",Connector,TDB
+,,“audio”,ENUM,"{ ""force-dvi"", ""off"", ""auto"", ""on"" }",Connector,TBD
+,SDVO-TV,“mode”,ENUM,"{ ""NTSC_M"", ""NTSC_J"", ""NTSC_443"", ""PAL_B"" } etc.",Connector,TBD
+,,"""left_margin""",RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,"""right_margin""",RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,"""top_margin""",RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,"""bottom_margin""",RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,“hpos”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,“vpos”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,“contrast”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,“saturation”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,“hue”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,“sharpness”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,“flicker_filter”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,“flicker_filter_adaptive”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,“flicker_filter_2d”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,“tv_chroma_filter”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,“tv_luma_filter”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,“dot_crawl”,RANGE,"Min=0, Max=1",Connector,TBD
+,SDVO-TV/LVDS,“brightness”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+CDV gma-500,Generic,"""Broadcast RGB""",ENUM,"{ “Full”, “Limited 16:235” }",Connector,TBD
+Poulsbo,Generic,“backlight”,RANGE,"Min=0, Max=100",Connector,TBD
+,SDVO-TV,“mode”,ENUM,"{ ""NTSC_M"", ""NTSC_J"", ""NTSC_443"", ""PAL_B"" } etc.",Connector,TBD
+,,"""left_margin""",RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,"""right_margin""",RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,"""top_margin""",RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,"""bottom_margin""",RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,“hpos”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,“vpos”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,“contrast”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,“saturation”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,“hue”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,“sharpness”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,“flicker_filter”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,“flicker_filter_adaptive”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,“flicker_filter_2d”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,“tv_chroma_filter”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,“tv_luma_filter”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+,,“dot_crawl”,RANGE,"Min=0, Max=1",Connector,TBD
+,SDVO-TV/LVDS,“brightness”,RANGE,"Min=0, Max= SDVO dependent",Connector,TBD
+armada,CRTC,"""CSC_YUV""",ENUM,"{ ""Auto"" , ""CCIR601"", ""CCIR709"" }",CRTC,TBD
+,,"""CSC_RGB""",ENUM,"{ ""Auto"", ""Computer system"", ""Studio"" }",CRTC,TBD
+,Overlay,"""colorkey""",RANGE,"Min=0, Max=0xffffff",Plane,TBD
+,,"""colorkey_min""",RANGE,"Min=0, Max=0xffffff",Plane,TBD
+,,"""colorkey_max""",RANGE,"Min=0, Max=0xffffff",Plane,TBD
+,,"""colorkey_val""",RANGE,"Min=0, Max=0xffffff",Plane,TBD
+,,"""colorkey_alpha""",RANGE,"Min=0, Max=0xffffff",Plane,TBD
+,,"""colorkey_mode""",ENUM,"{ ""disabled"", ""Y component"", ""U component"" , ""V component"", ""RGB"", “R component"", ""G component"", ""B component"" }",Plane,TBD
+,,"""brightness""",RANGE,"Min=0, Max=256 + 255",Plane,TBD
+,,"""contrast""",RANGE,"Min=0, Max=0x7fff",Plane,TBD
+,,"""saturation""",RANGE,"Min=0, Max=0x7fff",Plane,TBD
+exynos,CRTC,“mode”,ENUM,"{ ""normal"", ""blank"" }",CRTC,TBD
+i2c/ch7006_drv,Generic,“scale”,RANGE,"Min=0, Max=2",Connector,TBD
+,TV,“mode”,ENUM,"{ ""PAL"", ""PAL-M"",""PAL-N""}, ”PAL-Nc"" , ""PAL-60"", ""NTSC-M"", ""NTSC-J"" }",Connector,TBD
+nouveau,NV10 Overlay,"""colorkey""",RANGE,"Min=0, Max=0x01ffffff",Plane,TBD
+,,“contrast”,RANGE,"Min=0, Max=8192-1",Plane,TBD
+,,“brightness”,RANGE,"Min=0, Max=1024",Plane,TBD
+,,“hue”,RANGE,"Min=0, Max=359",Plane,TBD
+,,“saturation”,RANGE,"Min=0, Max=8192-1",Plane,TBD
+,,“iturbt_709”,RANGE,"Min=0, Max=1",Plane,TBD
+,Nv04 Overlay,“colorkey”,RANGE,"Min=0, Max=0x01ffffff",Plane,TBD
+,,“brightness”,RANGE,"Min=0, Max=1024",Plane,TBD
+,Display,“dithering mode”,ENUM,"{ ""auto"", ""off"", ""on"" }",Connector,TBD
+,,“dithering depth”,ENUM,"{ ""auto"", ""off"", ""on"", ""static 2x2"", ""dynamic 2x2"", ""temporal"" }",Connector,TBD
+,,“underscan”,ENUM,"{ ""auto"", ""6 bpc"", ""8 bpc"" }",Connector,TBD
+,,“underscan hborder”,RANGE,"Min=0, Max=128",Connector,TBD
+,,“underscan vborder”,RANGE,"Min=0, Max=128",Connector,TBD
+,,“vibrant hue”,RANGE,"Min=0, Max=180",Connector,TBD
+,,“color vibrance”,RANGE,"Min=0, Max=200",Connector,TBD
+omap,Generic,“zorder”,RANGE,"Min=0, Max=3","CRTC, Plane",TBD
+qxl,Generic,"“hotplug_mode_update""",RANGE,"Min=0, Max=1",Connector,TBD
+radeon,DVI-I,“coherent”,RANGE,"Min=0, Max=1",Connector,TBD
+,DAC enable load detect,“load detection”,RANGE,"Min=0, Max=1",Connector,TBD
+,TV Standard,"""tv standard""",ENUM,"{ ""ntsc"", ""pal"", ""pal-m"", ""pal-60"", ""ntsc-j"" , ""scart-pal"", ""pal-cn"", ""secam"" }",Connector,TBD
+,legacy TMDS PLL detect,"""tmds_pll""",ENUM,"{ ""driver"", ""bios"" }",-,TBD
+,Underscan,"""underscan""",ENUM,"{ ""off"", ""on"", ""auto"" }",Connector,TBD
+,,"""underscan hborder""",RANGE,"Min=0, Max=128",Connector,TBD
+,,"""underscan vborder""",RANGE,"Min=0, Max=128",Connector,TBD
+,Audio,“audio”,ENUM,"{ ""off"", ""on"", ""auto"" }",Connector,TBD
+,FMT Dithering,“dither”,ENUM,"{ ""off"", ""on"" }",Connector,TBD
+,,"""colorkey""",RANGE,"Min=0, Max=0x01ffffff",Plane,TBD